The reincarnation of the 1965 musical 'On a Clear Day You Can See Forever' now begins with its leading man, a shrink named Dr. Mark Bruckner, addressing a 1974 meeting of the American Psychological Association and discussing a patient who apparently was someone else in a past life, a someone with whom this doctor fell in love. When the star of the new Broadway version, Harry Connick Jr., starts to lecture, you're immediately put in mind of Al Gore. The craggy crooner, who plays opposite the gorgeously voiced Chicago star Jessie Mueller in a troubled and perplexing show that is hardly the best vehicle for her Broadway debut, has a physical resemblance to the handsome former vice president, and he also embodies some of Gore's signature stiffness. But among many inconvenient truths in this revival, with a radically retooled new book by Peter Parnell and direction and reconception by Michael Mayer, Connick — the big star on the marquee — is just not given a character or persona within which he can rest easy.